#include <stdio.h>

int main()
{
	int arr[4] = { 0 };
	int i = 0;
	while (i < 4)
	{
	
		scanf_s("%d", &arr[i]);
		i++;
	
	}
	int max = arr[0];
	 i = 1;
	while (i < 4)
	{
		if (arr[i] > max)
		{
			max = arr[i];
		}
		i++;

	}
	printf("%d",max);

	return 0;
}